Model car racing track

ABSTRACT

A model car racetrack with at least one model car which is guided along a lane, a roadway which defines the lane, wherein the roadway has at least one bus bar which extends in the direction of the lane, and a transformer arrangement comprising a primary element and a secondary element for contact-free energy transmission from the roadway to the model car, wherein the bus bar is the primary element of the transformer arrangement and the model car represents the secondary element of the transformer arrangement for coupling in the electromagnetic field which is produced by the primary element.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a model car racing track. More specifically,the invention relates to a model car racing track having a transformerarrangement for contact-free energy transmission from the track to amodel car, where the track bus bar represents the primary element of thetransformer arrangement, and the model car represents the secondaryelement for coupling in the electromagnet field generated by the primaryelement.

2. Description of Related Art

A model car racing track, also known as a slot-car track or slot track,is a technical apparatus with which electrically-driven model cars canbe driven in a guided manner along lanes, wherein a guide keel on themodel car engages in a slot on the track.

The model car racing track comprises a track which can for example beassembled from a plurality of track sections which can be pluggedtogether. The track can have two lanes which in each case possess a slotfor guiding a model car and two bus bars for the current supply of theelectrical drive of the model vehicles which can be moved along therespective lane. Current collectors on the respective model cars arethereby in contact with the respective bus bar in order to guarantee atransmission of electrical energy. The speed and braking behavior of therespective model car can in each case be controlled using a hand-heldcontroller. However, when driving round a curve for example, due tocentrifugal forces acting on the model cars it can happen that thecontact between the bus bar and the current collector of the model caris interrupted, with the consequence that the energy supply to theelectrical drive of the model car is interrupted and the model car losesspeed.

SUMMARY OF THE INVENTION

The invention is based on the object of showing a way how aninterruption-free supply with electrical energy of model cars of such amodel car racing track can be guaranteed.

According to the invention, this object is achieved through a model carracing track of the aforementioned type with the characterizing featuresof the independent claims. Advantageous embodiments of the invention aredescribed in the further dependent claims.

The above and other objects, which will be apparent to those skilled inthe art, are achieved in the present invention which is directed to amodel car racing track having at least one model car guided along a laneand a track defining the lane, wherein the track has at least one busbar extending in the direction of the lane, including a transformerarrangement with a primary element and a secondary element forcontact-free and interruption-free transmission of energy and controlsignals from the track to the model car, wherein the bus bar is arrangedon a surface of the track and is the primary element of the transformerarrangement extending in the direction of the lane, and the model carcomprises the secondary element of the transformer arrangement forcoupling in the electromagnetic field generated by the primary element,wherein the secondary element has a winding or a plurality of windings,wherein the winding or plurality of windings defines a screw vector (S)extending horizontally in a width direction Y which extendssubstantially at right angles to the direction of the lane.

A rotation vector (R) of the electromagnetic field generated by theprimary element points substantially in the direction of the lane. Thesecondary element has a main direction of extension (H) which issubstantially at right angles to the direction of the lane.

At least one second lane with at least one second bus bar is provided,along which a second model car is guided along the lane, wherein anelectrical current with a first frequency is applied to the first busbar and a second electrical current with a second frequency is appliedto the second bus bar, wherein the first frequency is different from thesecond frequency.

The second frequency is preferably at least one and a half times thefirst frequency, for example, the first frequency may be 400 kHz and thesecond frequency may be 600 kHz.

The at least one lane may have two parallel bus bars extending in thedirection of the lane, where the two bus bars of a lane are wiredelectrically in parallel or wired electrically in series.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The figures are for illustration purposes only and arenot drawn to scale. The invention itself, however, both as toorganization and method of operation, may best be understood byreference to the detailed description which follows taken in conjunctionwith the accompanying drawings in which:

FIG. 1 shows a schematic sectional representation of a preferredembodiment of a model car racing track according to the invention;

FIG. 2 shows a schematic representation of a transformer arrangementwhich is used in the model car racing track shown in FIG. 1;

FIG. 3 shows a view from above of the first substrate element shown inFIG. 2;

FIG. 4 shows a view from below of the second substrate element shown inFIG. 2;

FIG. 5 shows an operating scenario of the model car racing track shownin FIG. 1;

FIG. 6 shows a first wiring variant of bus bars of a track with twolanes;

FIG. 7 shows a second wiring variant of bus bars of a track with twolanes; and

FIG. 8 shows a further exemplary embodiment of a model car racing trackaccording to the invention, with a track provided with a bus bar foreach lane of the track, which has several lanes.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In describing the preferred embodiment of the present invention,reference will be made herein to FIGS. 1-8 of the drawings in which likenumerals refer to like features of the invention.

For this purpose, in a model car racing track of the aforementionedtype, according to the invention a transformer arrangement comprising aprimary element and a secondary element for contact-free energytransmission from the track to the model car is provided, wherein thebus bar is the primary element of the transformer arrangement and themodel car comprises the secondary element of the transformer arrangementfor coupling in the electromagnetic field generated by the primaryelement. In other words, the model car racing track has an air-coretransformer for contact-free energy transmission, wherein the primaryelement performs the function of a primary coil or winding and thesecondary element performs the function of a secondary coil or winding.

This has the advantage that no temporary interruption of an electricalcontact between a bus bar and a current collector, and thus nointerruption of the supply with electrical energy, can occur.Furthermore, an unmodified track with a particularly simple structurecan be used in which the bus bars are configured as conductors extendingin the direction of travel or lane direction. In addition to thetransmission of operating energy, control signals can also betransmitted with the transformer arrangement, for example in order toaccelerate or brake the model car, for example in that these controlsignals are modulated with a higher frequency and filtered out again onthe model car side.

According to a preferred embodiment, a rotation vector of theelectromagnetic field generated by the primary element pointssubstantially in the direction of the lane. The bus bar, configured as aconductor extended in the direction of the lane, forms a magnetic field,the field lines of which have the form of closed, concentric circles orellipses around the bus bar. In this case a rotation vector of themagnetic field, which stands perpendicular to the concentric circles,points in the direction of the lane. “Substantially” is therebyunderstood to mean within usual manufacturing tolerances. Thus, anunmodified track with a particularly simple structure can be used inwhich the bus bars are configured as conductors extending in thedirection of travel or lane direction. Tracks with integrated coilelements, which are complex to manufacture, are not necessary.

According to a further preferred embodiment, the secondary element has amain direction of extension which is substantially at right angles tothe direction of the lane.

According to a further preferred embodiment, the secondary element has awinding or a plurality of windings, wherein the winding or plurality ofwindings defines a screw vector which extends substantially at rightangles to the direction of the lane. The plurality of windings defines amain direction of extension of the secondary element in the helicaldirection of the secondary element. Thus, the secondary element can havea different orientation than the primary element, which makes possible aconstruction-space-saving arrangement within the model car.

According to a further preferred embodiment, at least one second lanewith at least one second bus bar is provided, along which a second modelcar is guided along the lane, wherein an electrical current with a firstfrequency is applied to the first bus bar and a second electricalcurrent with a second frequency is applied to the second bus bar,wherein the first frequency is different from the second frequency. Inthis way, mutual influences through the inductive coupling-in ofelectrical energy are avoided or at least reduced.

According to a further preferred embodiment, the second frequency is atleast one and a half times the first frequency. In this way, a mutualinfluence through the inductive coupling-in of electrical energy can bereduced particularly effectively.

According to a further preferred embodiment, the first frequency is 400kHz and the second frequency 600 kHz. Through the selection of thesefrequencies, a particularly effective energy transmission can beachieved on the one hand, and on the other hand minimal interferencewith other electro-technical or electronic devices in the vicinity ofthe model car racing track can be achieved.

According to a further preferred embodiment, the at least one track hastwo parallel bus bars extending in the direction of the lane. Here too,an unmodified track with a particularly simple structure can be used inwhich the bus bars are configured as conductors extending in thedirection of travel or lane direction.

According to a further preferred embodiment, the two bus bars are wiredelectrically in parallel. In this way, a doubled conductor cross sectionis made available, so that a doubled current strength can be applied tothe bus bar elements. Furthermore, this means that, in the event of aninterruption of one of the two bus bar elements, electrical currentstill flows through the other bus bar element. This increases thereliability of the supply of a model car with electrical energy.

According to a further preferred embodiment, the two bus bar elementsare wired electrically in series. Thus, the two bus bar elements form adouble loop, which further improves the efficiency of the energytransmission.

The invention is described in more detail in the following withreference to the drawings.

A model car racing track 2, also known as a slot-car track or slottrack, is represented in FIG. 1.

The model car racing track 2 has a track 4 made up of a plurality oftrack sections which can be plugged together with, in the presentexemplary embodiment, two lanes 6 a, 6 b, each for a model car 10. Onlyone model car 10 is illustrated in FIG. 1.

In the present exemplary embodiment, the track 4 has a recess 8 a, 8 bassigned to each lane 6 a, 6 b which is arranged centrally relative tothe lane and in which a guide element 30, for example a guide pin orguide keel of the model car 10, engages and so effects a guidance of themodel car 10 along the respective lane, in this case the lane 6 a.

Furthermore, in the present exemplary embodiment the track 4 has in eachcase two bus bars 14 a, 14 b, 14 c, 14 d arranged on each side of therespective recess 8 a, 8 b which are assigned to the first lane 6 a orthe second lane 6 b. In the present exemplary embodiment, the first andsecond bus bars 14 a, 14 b, 14 c, 14 d have a u-formed profile in crosssection and are pressed into further recesses in the track 4. Indeparture from the present exemplary embodiment, the first and secondbus bars 14 a, 14 b, 14 c, 14 d can also have a different profile incross section.

The bus bars 14 a, 14 b, 14 c, 14 d are in each case formed in a singlepiece and of the same material. Furthermore, the bus bars 14 a, 14 b, 14c, 14 d are manufactured of a magnetic material. In this way, the modelcar 10 can be held in the lane 6 a through magnetic force by means of apermanent magnet (not shown) which interacts with the bus bars 14 a, 14b.

As will be explained later, the two bus bar pairs 14 a, 14 b or 14 c, 14d form a primary element 18 of a transformer arrangement 16 forcontact-free energy transmission to the model car 10.

The transformer arrangement 16 for contact-free energy transmission tothe model car 10 also includes a secondary element 20 assigned to themodel car 10 for coupling in the electromagnetic field generated by theprimary element 18.

In the present exemplary embodiment, the secondary element 20 is a coilarrangement 22.

In addition to the transmission of operating energy, control signals canalso be transmitted with the transformer arrangement 16, for example inorder to accelerate or brake the model car 10, for example in that thesecontrol signals are modulated with a higher frequency and filtered outagain on the model car side.

Reference is now made, in addition, to FIG. 2, which for reasons ofsimplicity only shows the first lane 6 a of the two lanes 6 a, 6 b.However, the following explanations also apply analogously to the secondlane 6 b with the recess 8 b and the bus bars 14 c and 14 d.

FIG. 2 shows that both the recess 8 a and also the two bus bars 14 a, 14b each have a main direction of extension H pointing along the lane 6 ain the direction of travel, in which direction its dimensions aresignificantly greater than in the direction of the other directions ofextension.

Furthermore, FIG. 2 shows that the coil arrangement 22 has a substrate12. In the present exemplary embodiment, the substrate 12 has a firstsubstrate element 24 a and a second substrate element 24 b as well as aferrite core 26 arranged between the first substrate element 24 a andthe second substrate element 24 b.

In the present exemplary embodiment, the first substrate element 24 aand the second substrate element 24 b are in each case a circuit board.The circuit boards have a basic shape extending in a planar manner, inthe present exemplary embodiment a rectangular basic shape, with in eachcase an upper side and an underside opposite the upper side. Theyconsist in each case of an electrically insulating material andconductor paths arranged thereon. Fiber-reinforced plastic is forexample commonly used as insulating material. The conductor paths arefor example etched from a thin coating of copper applied previously tothe insulating material.

In the present exemplary embodiment, conductor paths on the upper sideof the first substrate element 24 a form a plurality of first coilportions 28 a, while in the present exemplary embodiment furtherconductor paths on the underside of the second substrate element 24 bform a plurality of second coil portions 28 b. In each case one of thefirst coil portions 28 a and one of the second coil portions 28 btogether form a coil winding of the coil arrangement 20.

For this purpose, connecting lines (not shown) are provided which extendthrough the first substrate element 24 a and the second substrateelement 24 b and connect the respective first coil portions 28 a withthe respective second coil portion 28 b in an electrically conductivemanner. Thus, in the present exemplary embodiment the coil portions 28a, 28 b form three coil windings. However, five to eight coil windingscould also be provided.

Furthermore, FIG. 2 shows that the ferrite core 26 is arranged with itsupper side on an underside of the first substrate element 24 a and theunderside of the ferrite core 26 is arranged on an upper side of thesecond substrate element 24 b.

The ferrite core 26 is a component made of ferrite which, as core of thecoil arrangement 22, increases its inductance or guides the magneticfield. Ferrites are understood to be materials comprising poorlyelectrically conductive or non-conductive ferrimagnetic ceramicmaterials made from the iron oxide haematite (Fe₂O₃), magnetite (Fe₃O₄)and/or from further metal oxides. Depending on the composition, ferritesare hard magnetic or soft magnetic.

The coil windings formed by the respective first coil portions 28 a andsecond coil portions 28 b have a screw vector S which, as illustrated inFIG. 2, lies substantially within the plane of the substrate 12 anddescribes the helical configuration of the coil windings of the coilarrangement 22.

It can also be seen that the screw vector S is arranged substantially atright angles to the main direction of extension H of the bus bars 14 a,14 b.

Furthermore, FIG. 2 shows that the substrate 12 has a first direction ofextension I, a second direction of extension II and a third direction ofextension III.

In the present exemplary embodiment, the first direction of extension Iextends in a height direction Z between the first substrate element 24 aand the second substrate element 24 b. The second direction of extensionII extends at right angles to the first direction of extension I in thedirection of the screw vector S or in a width direction Y. Furthermore,the third direction of extension III extends at right angles to thefirst direction of extension I and to the second direction of extensionII in the direction of the main direction of extension H or in a depthdirection X.

In the present exemplary embodiment, the substrate 12, the firstsubstrate element 24 a, the second substrate element 24 b and theferrite core 26 in each case have significantly greater dimensions inthe direction of the second direction of extension II and the thirddirection of extension III than in the direction of the first directionof extension I. In other words, they in each case have a rectangular, inparticular plate-formed basic shape.

Reference is now made, in addition, to FIGS. 3 and 4.

FIGS. 3 and 4 show that the first coil portions 28 a and the second coilportions 28 b have an elongated form, i.e., their respective dimensionsin the direction of the third direction of extension III are greaterthan in the direction of the second direction of extension II.Furthermore, the first coil portions 28 a and the second coil portions28 b extend at an angle to the second direction of extension II which isunequal to a right angle. In the present exemplary embodiment, the firstcoil portions 28 a and the second coil portions 28 b extend at an angleof 75° to 85° or 95° to 110° to the second direction of extension II.

In this way, a coil arrangement 22 is provided which is particularlycompact and takes up little construction space. Furthermore, themanufacture of the coil arrangement 22 is simplified in each casethrough the planar formation of the first coil portions 28 a and secondcoil portion 28 b on the upper or underside of the substrate 12, sinceplanar or thick film technology can be used for this purpose.

The operation of the model car racing track 2 will be explained withadditional reference to FIG. 5, wherein, for reasons of simplicity, ofthe primary element 18, only the first bus bar 14 a of the two bus bars14 a, 14 b of the first lane 6 a is illustrated.

In operation, an alternating current with a frequency of 400 kHz flowsthrough the bus bar 14 a. A magnetic field M is formed around the busbars 14 a with concentric field lines extending around the bus bar 14 a.The course of the field lines can be described by a rotation vector Rstanding perpendicular to the plane which is described by the fieldlines.

The field lines pass through the secondary element 20 or the coilarrangement 22 and generate, through induction, an electrical voltage inthe secondary element 20. The electrical voltage induced in thesecondary element 20 can then be used to supply an electrical drive ofthe model car 10, so that the model car 10 can move in the direction oftravel F predetermined by the main direction of extension H of therecess 8 a or the bus bar 14 a. Thus, the direction of travel F and therotation vector R are oriented substantially at right angles to oneanother. “Substantially” is thereby understood to mean within usualmanufacturing tolerances.

A regulation of the speed of the model car 10 can thereby be achievedthrough a change in the current strength of the electrical current whichflows through the bus bars 14 a, 14 b.

Due to the contact-free transmission of electrical energy, contactinterruptions, such as occur in the prior art, can be avoided andinterruption of the supply with electrical energy no longer occurs.

In addition to the first lane 6 a shown in FIG. 1, in the presentexemplary embodiment the second lane 6 b for a second model car (notshown) is provided which has the same structure as the first lane 6 a.However, in order to avoid, as far as possible, interferences betweentwo model cars 10 and thus disturbances in the energy transmission, thebus bars 14 c, 14 d of the second lane 6 b are flowed through by anelectrical current with a frequency which is at least one and a halftimes as high as the first frequency. In the present exemplaryembodiment, the second frequency is 600 kHz.

Reference is now made, in addition, to FIGS. 6 and 7, which show by wayof example wiring variants of the two bus bar pairs 14 a, 14 b or 14 c,14 d with reference to the first lane 6 a of the two lanes 6 a, 6 b ofthe track 4.

FIG. 6 shows a first wiring variant in which the two bus bars 14 a, 14 bof the first lane 6 a are wired electrically in parallel. This allowsuse to be made of the doubled conductor cross section of the two busbars 14 a, 14 b, so that a doubling of the current strength applied tothe bus bars 14 a, 14 b becomes possible.

FIG. 7 shows a second wiring variant in which the two bus bars 14 a, 14b of the first lane 6 a are wired electrically in series. Thus, the twobus bars 14 a, 14 b form a double conductor loop, so that the efficiencyof the energy transmission is improved.

Reference is now made to FIG. 8.

This shows a second exemplary embodiment of a track 4′ which, incontrast to the track 4 illustrated in FIG. 1, only has two recesses 8a, 8 b, in each of which a further exemplary embodiment of a bus bar 14a′, 14 b′ is fitted.

The structure of the bus bars 14 a′, 14 b′ according to this exemplaryembodiment will be explained with reference to the bus bar 14 b′assigned to the second lane 6 b.

The bus bar 14 b′ has a u-formed profile with a groove base 32 and twoflanges 34 extending from the groove base 32 which in the presentexemplary embodiment extend parallel. Extending from each of the flanges34 is a tongue 36 which extends within the plane of the surface of thetrack 4′.

The bus bars 14 a′, 14 b′ according to this exemplary embodiment are ineach case formed in a single piece and of the same material.Furthermore, according to this exemplary embodiment the bus bars 14 a′,14 b′ are manufactured of a magnetic material. In this way, here too themodel car 10 can be held in the lane 6 a through magnetic force by meansof a permanent magnet (not shown) which interacts with the bus bar 14a′. In particular, the two tongues 36 provide an enlarged surface onwhich the magnetic force can act, so that a magnet of reduced size canbe used in the model car 10 which takes up less construction space.

Furthermore, the two bus bars 14 a′ 14 b′ are fitted into the respectiverecesses 8 a, 8 b such that the u-formed bus bars 14 a′, 14 b′ are openin an upwards direction, so that the guide element 30, for example a pinof the model car 10, can engage in the u-formed bus bar 14 a′ in orderin this way to guide the model car 10 along the lane 6 a defined by therecess 8 a. Thus, this track 4′ has a particularly simple structure withonly one bus bar 14 a′, 14 b′, in the present exemplary embodimentarranged centrally, for each of the lanes 6 a, 6 b, wherein the bus bars14 a′, 14 b′ in each case have a double function, namely as bus bar andas guide groove for the model car.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

Thus, having described the invention, what is claimed is:
 1. A model carracing track having at least one model car guided along a lane and atrack defining the lane, wherein the track has at least one bus_barextending in the direction of the lane, including a transformerarrangement with a primary element and a secondary element forcontact-free and interruption-free transmission of energy and controlsignals from the track to the model car, wherein the bus_bar is arrangedon a surface of the track and is the primary element of the transformerarrangement extending in the direction of the lane, and the model carcomprises the secondary element of the transformer arrangement forcoupling in the electromagnetic field generated by the primary element,wherein the secondary element has a winding or a plurality of windings,wherein the winding or plurality of windings defines a screw vector (S)extending horizontally in a width direction Y which extendssubstantially at right angles to the direction of the lane.
 2. The modelcar racing track of claim 1, wherein a rotation vector (R) of theelectromagnetic field generated by the primary element pointssubstantially in the direction of the lane.
 3. The model car racingtrack of claim 1, wherein the secondary element has a main direction ofextension (H) which is substantially at right angles to the direction ofthe lane.
 4. (canceled)
 5. The model car racing track of claim 1,wherein at least one second lane with at least one second bus_bar isprovided, along which a second model car is guided along the lane,wherein an electrical current with a first frequency is applied to thefirst bus_bar and a second electrical current with a second frequency isapplied to the second bus_bar, wherein the first frequency is differentfrom the second frequency.
 6. The model car racing track of claim 5,wherein the second frequency is at least one and a half times the firstfrequency.
 7. The model car racing track of claim 5, wherein the firstfrequency is 400 kHz and the second frequency 600 kHz.
 8. The model carracing track of claim 1, wherein the at least one lane has two parallelbus_bars extending in the direction of the lane.
 9. The model car racingtrack of claim 8, wherein the two bus_bars of a lane are wiredelectrically in parallel.
 10. The model car racing track of claim 8,wherein the two bus_bars of a lane are wired electrically in series. 11.The model car racing track of claim 7, wherein the at least one lane hastwo parallel bus bars extending in the direction of the lane.
 12. Themodel car racing track of claim 11, wherein the two bus bars of a laneare wired electrically in parallel.
 13. The model car racing track ofclaim 11, wherein the two bus bars of a lane are wired electrically inseries.